Method of making carbamoyl sulfoxide derivatives

ABSTRACT

Intermediate compounds and the process of manufacturing herbicidally active sulfoxide and sulfone compounds are described herein. The intermediate compounds have the following generic formula:   WHEREIN R is selected from the group consisting of halophenyl, phenalkyl, substituted phenalkyl, wherein said substituents can be selected from halogen, alkyl and haloalkyl; R1 and R2 can be the same or different and can be selected from the group consisting of lower alkyl, cycloalkyl, alkenyl, alkynyl and benzyl. The active compounds are made by reacting the intermediate compound with an oxidizing agent.

United States Patent [191 Till'es et al.

[ METHOD OF MAKING CARBAMOYL .SULFOXIDE DERIVATIVES [75] Inventors: Harry Tilles, El Cerrito; Alan A.

MacDonald, Albany, both of Calif.

[73] .Assignee: Stauffer Chemical Company,

Westport, Conn.

[ Notice: The portion of the term of this patent subsequent to July 22, 1992, has been disclaimed.

\[22] Filed: June 18, 1973 [2i] Appl. No.1 371,329

Related US. Application Data {[63] Continuation-impart of Ser. No. 280,393, Aug. 14,

1972, abandoned.

[52] [1.5. CI 260/551 R; 260/455 A; 260/607 A;

71/100; 71/98 [51] Int. Cl. C07C 103/76; C07C 147/14 [58] Field of Search 260/551, 470, 479

[56] References Cited UNITED STATES PATENTS 3,326,663 6/1967 Soloway et al 71/103 *July 29, 1975 Primary Examiner-Harry I. Moatz Attorney, Agent, or Firm-Daniel C. Block [57] ABSTRACT Intermediate compounds and the process of manufacturing herbicidally active sulfoxide and sulfone compounds are described herein. The intermediate compounds have the following generic formula:

2 Claims, No Drawings 1 MAKTNG .CARBAMOYL SULFOXIDE v.DERIYATWES y CROSS-REFERENCE Thisapplicaition is a continuation-impartof application Ser. No. 280,393, filed Aug. l4,.-19 72, now abari;

doned.

METHOD OF wherein n can be l or 2; R can be selected from th e wherein R, R and R have been defined above. The reaction is carried out in the presence of a solvent such as chloroform, methylene chloride, benzene or toluene, and at a reduced temperature of from about -25C. to about 65C. The amount of oxidizing agent used must be at least one molar equivalent to form the sulfoxide derivative and at least two molar equivalents to form the sulfone derivatives.

The thiocarbamate compounds are known herbicides and their method ofsynthesis is known; see U.S. Pat. Nos. 2,913,327, 2,983,747, 3,133,947, 3,175,897 and 3,185,720 for example. However, the use of these thiocarbamates as reactive intermediates to form other compounds that also have pesticidal activity is unexpected.

chloride in a reaetionvessel.The temperature of this solution wasi regulatedto 30C,, whereinfiA g. 0,017.

mole) of S -4-ch lorobenzyl diethylthiocarbama-te, was added over a period of one minute. Atjheendpf-the addition, a rapid reflux began and the temperature rose to 41C. The reaction was allowe'd to take place for about 40 minutes, wherein the mixture was cooled and filtered and the cake was washed with two portions of cc. of methylene chloride. The combined filtrate was washed with four portions of .50 cc. of 5%sodium carbonate solution and two portions of 50 cc. of water, then dried over magnesium sulfate and concentrated in a rotary evaporator, first under a water pump vacuum and finally underhigh vacuum to, yield 4.4g. of product, n 1.5425; After standing for ashort period, the liquid crystallized to yield-a product of 4,4 g. having mp. of 64-7 2C.

EXAMPLE 2 In order to illustrate the merits of the present invention the following examples are provided:

EXAMPLE 1 A solution was formed containing 10.7 g. (0.0525 mole) of m-chloroperoxybenzoic acid in 200 cc. of methylene chloride. This" solution was cooled to 16C., wherein 12.9 ,,g. 3(0105... mole) of S-4- chlorobenzyl diethylthiocarbamate was added over a periodof four minutes.' The reaction was allowed to take place forone hour, wherein the temperature was allowed to goto -5C. The temperature was held at 5-C.' for another 30 minutes, wherein the temperature was allowed to reach 2l.5C. The solution was then cooled in an ice bath, wherein the cold mixture was filtered and the cake was washed with two portions of 25 cc. of methylene chloride. The combined filtrate was .finally under high vacuum to yield 12.3 g. of product,

L030 1.5678. This product was further distilled to yield 10.6 g. of product, n 1.5680.

EXAMPLE 3 In a 500 ml. 3-necked flask equipped with a thermometer, mechanical stirrer, and addition device were placed 250 ml. of methylene chloride and 12.6 g. (0.05 mole) of S-benzyl ethylisobptylthiocarbamate dissolved in 25 ml. of methylene chloride. Stirring was begun and the temperature lowered to 30C. with dry ice. Then, 8.7 g. (0.05 mole) of mchloroperoxybenzoic acid was rapidly added and the temperature held at 30C. for 15 minutes. The tem- .perature then was allowed to rise to 0C. over a 30 minute period and then up to 4C. The cold mixture was filtered and the filtrate washed with three 50 ml. portions of 5% potassium carbonate solution, two 50 ml. portions of water and then dried over magnesium sul fate and stripped to obtain a colorless Viscous liquid product weighing l3.5 g., m, l.54( )3.

EXAMPLE 4 Y A solution was formed containing l7.3 g. (0.10 mole) of' m-chloroperoxybenzoic'acid in 300 ml. of

methylene chloride. This mixture was warmed to 30C. whereupon 12.6 g. (0.05 mole) of S-benzyl manner starting with the appropriate starting materials as outline d above. The following is a table .of compounds: representative of, those embodied by the present invention. Compound numbers have been assigned to them and are used for identification throughout the balance of the specification.

TABLE I Compound Herbicidal Screening Tests As previously mentioned, the novel compounds herein described are phytotoxic compounds which are useful and valuable in controlling various plants species. Compounds of this invention are tested as herbicides in the following manner.

Pre-emergence Herbicide Screening Test Using an analytical balance, mg. of the compound to be tested is weighed out on a piece of glassine weighing paper. The paper and compound are placed in a ml. wide-mouth bottle and 3 ml. of acetone containing 1% Tween 20 is added to dissolve the compound. If the material is not soluble in acetone, another solvent such as water, alcohol or dimethylformamide (DMF) is used instead. When DMF is used, only 0.5 ml. ,or less-is used to dissolve the compound and then another solvent is used to make the volume up to 3 ml. The 3 ml. of solution is sprayed uniformly on the soil contained in a small Styrofoam flat one day after planting weedseeds in the flat of soil. A No. 152 DeVilbiss atomizer is used to apply the spray using compressed air at a pressure of 5 lb./sq. in. The rate of application is 8 lb./.acr-e and the spray volume is 143 gaL/acre. I

On the day preceding treatment, the Styrofoam flat, which is 7 inches long, 5 inches wide and 2.75 inches deep, is filled to a depth of 2 inches with loamy-sand soil. Seeds of seven different weed species are planted in individual rows using one species per row across the width of the flat. The seeds are covered with soil so that they are planted at a depth of 0.5 inch; The seedsiused are hairy crabgrass (Digitaria sanguinalis), yellow foxtail (Setaria glauca), redroot pigweed (Amaranthus retroflexus), Indian mustard (Brassica junceq) and curlyn dock (Rumex crispus). Ample seeds are planted to give about 20 to 50 seedlings per row after emergence depending on the size of theplants.

After treatment, the flats are placed in the -greenhouse at a temperature of 70 to 85F and-watered by sprinkling. Two weeds after treatment the degree of injury or control is determined by comparison, with untreated check plants of the same age. Theinjury rating from 0 to 100% is recorded for each species as percent control with 0% representing no injuryand 100% representing complete kill. 5 I 1 Post-emergence Herbicide Screening Test Seeds o f six plant species, i'ncliid'i'ng hairy crabgrass, watergrass, red oat, mustard, curly dock and Pinto beans (Phaseolus vulgaris) are planted in the Styrofoam flats as described above for pr e-emergence screening. The flats are placed in the..gfre"enhouse at to F. and watere d daily with a spri n'kl er -About 10 to lgta days after planting when theprimary leaves of the bean plants are almost fully expanded and the first trifoliate leaves are just starting to form, the plants are sprayed. The spray is prepared byyveighing out 20 mg. of the test compound, dissolving itin 5 ml. of aceton'e qcontaining I% Tween 20 and then adding 5 ml. of water. The solution is sprayed on the foliage using a No. 152 DeVilbiss atomizer at an air-pressure of 5 lb./sq. in. The spray concentration is 0.2 andthe'rate is 8 lb./acr e. The spray volume is 476 gal/acre.

Injury ratings are recorded 14 days after treatment. The rating system is the same asdescribed above for the preerriergence test. The injury'symptoms are also the same as listed above for the pre-emergence test, except that IG (inhibited germination) is not used since the seeds have already germinated before treatment in the post emergence screening test.

The results of these tests are shown in Table II.

TAB-LE1}! w HERBICIDAL ACTIVITT SCREENING RESULTS Per Cent Control at 8 lb./A

Compound I NQ.- Pre-emergence 1.. '.--"'Post-emergenc I IO i 45 2 s9 as 3 s j 0 :4 5 :5 13 5 99.7 93 6 99.9 87 7 99 87 8 76 75 9; 88 60 1,0 90 I 76 l l 91 25 I2 75 l5 I3 93 I 32 I4, 87 72 I5" 82 48 I6 27 l0 I7 37 17 18 57 20 I9 68; 40 2O FY 17 42 TABLE ll-Continued HERBICIDAL ACTIVITY SCREENING RESULTS Per Cent Control* at 8 lb./A

Compound .No. Pre-emergence Post-emergence 22 92 63 23 9O 47 24 90 75 25 94 72 26 9 l 75 .27 27 15 3 1 l4 34 88 73 35 99 95 .36 46 48 .37 100 85 138 98 9 l 139 94 87 4O 96 74 41 78 43 42 90 O 43 37 37 44 87 62 45 90 75 46 64 63 47 8 l 74 48 90 77 49 96 79 :50 95 85 .5 l 80 70 :5 2 92 76 :5 3 0 32 :54 49 57 55 69 73 56 86 53 .57 87 78 58 89 63 59 77 45 60 58 43 61 96 48 62 99 83 63 99 8 1 64 99.9 93 65 99.9 92 66 95 62 67 100 90 68 I00 86 69 93 77 70 I00 82 7 1 I00 82 72 100 88 l 3 73 80 74 9 l 85 75 99.6 85 76 96 91 77 64 83 78 98 83 79 88 78 80 9 l 79 8 1 W0 91 82 I00 92 .83 38 32 .84 90 78 1B5 21 0 :87 62 0 88 42 0 89 67 40 Per Cent Control at lb./A Compound No. Pre-emergence Post-emergence Average for seven plant species in the pre-emergence test and for six plant species in the post-emergence test.

The compounds of the present invention can be used in any convenient form. Thus, the compounds can be made into emulsifiable liquids, emulsifiable concentrates, liquid, wettable powder, powders, granular or any other convenient form, and applied to the soil to control the undesired vegetation.

The terms lower alkyl, alkenyl and alkynyl are meant to include those compounds having straight or branched chain configurations having from 1 to 6 carbon atoms, inclusive.

What is claimed is:

l. A process for manufacturing a compound having the formula:

wherein n is 1 or 2; R is selected from the group consisting of halophenyl, phenalkyl, substituted phenalkyl wherein said substituents are selected from halogen, alkyl having 1-6 carbon atoms and haloalkyl having 1 to 6 carbon atoms; R and R can be the same or different and are selected from lower alkyl having 1 to 6 carbon atoms, cyclohexyl, alkylcyclohexyl, alkenyl, alkynyl and benzyl, comprising the steps of:

a. reacting an oxidizing agent selected from peracetic acid and m'chloroperoxybenzoic acid with a thiocarbamate in the presence of an inert solvent; said thiocarbamate having the formula:

l RSCN 2. The process of claim 1 wherein said oxidizin agent is m-chloroperoxybenzoic acid. 

1. A PROCESS FOR MANUFACTURING A COMPOUND HAVING THE FORMULA:
 2. The process of claim 1 wherein said oxidizing agent is m-chloroperoxybenzoic acid. 